Friday, December 5, 2014

In this issue of Echo Ireland I would like to talk about
some of the aerials used /portable (and at QTHR) and the means to fix them in
place when out /p.

In photo 1 above, you can see some aerials mounted on a small
portable mast that has been used many times, all the aerials on it are for
23cms (1.2ghz) the top one is a vertical and the others are various types of
beam aerials such as what would be classed as a regular type of beam, the
others are a loop Yagi, and a circular polarization type. In use there would be
some coaxial cable used to connect the transceiver to the aerial but on some
occasions the transceiver is screwed direct to the aerial and a remote lead
carrying the power, audio, video and TX/RX switching from the car to the mast
mounted transceiver.

Photo 2 above shows one of the stands used, it works on the
fact that you drive over the base of the stand and the weight of the car holds
it in place and it does not need any stays to hold it in place. This base unit
was the mk1 type; it was made when I had a 5 door sierra, and made as a fixed
item. It became awkward to transport in the boot model car I got next and the
base unit was left aside for a few years. The latest car is a hatchback and is
well able for it, but not long after using the base for a few times I got
someone to modify it, firstly he had to separate part of the base frame and
make it wider by inserting an extra
piece of box metal so some hinges could be wielded in place, also the rigid
support arm on its right side was cut away and its ends modified so that each
end was held in place to the base by a bolt and when one of them was removed
the unit could be folded flat for transporting and storage, the base can be
seen again in photo 3 below along with some of the mast bases that were bought / made over
the years.

In photo 3 above you can
see the various ways the aerials are used /portable whether attached to the car
or being held upright by other stands. Some of the masts would take a couple of
people to erect safely, but others could be attached to the towing eyes or the
tow bar. You should take care when you are on your own working /portable, you
could end up with some damaged aerials, or car as the pole with the aerials
attached could be to long and will be top heavy for you to manage the assembling
of the aerials and mast, and their dismantling, the dismantling part can be the
most dangerous regardless of the weather, as fatigue could set in after a long
day and with possibly cold / wet hands you
could lose your grip and have to repair a boom and a few elements on an aerial
or two, and remember if you are on a height you do not need a skyscraper of a
mast, if you are on your own just bring something you can safely manage by
yourself.

In photo 4 above you can
see some of the other aerials that did not make it onto the mast, these bow tie
aerials can be used individually or some of them could be placed into the panel
aerial case you see them resting on. (The panel aerial is for use between
195-197 MHZ.) When it comes to connecting your aerials to your transmitter other
than coaxial cable, the range of fittings can be bewildering as can be seen in
photo 5 below.

Photo 6 above shows a dish and on the bottom right of it is an
aerial that looks like a can, and it could be used as is for some local use, or
it can be used as a launcher and lined up to feed a dish like the one it is
sitting on, but some framing, and exact measurements would have to be done to
attach the can to the dish at the right distance but that is a job for another
day.

That’s it for this issue of Echo Ireland and indeed for
this year.

I would like to wish you all a Happy Christmas and a
Prosperous New Year.

Thursday, December 4, 2014

Hello and welcome to 030 of the HX files.

In this issue I would like to talk about some of the “few”
parts bought at the Friedrichshafen Rally in June.

In photo 1 bellow,

you can see some of the leads and parts
purchased, in the picture you maybe able to make out a couple of small monitors,
various leads, fittings, and a couple of RF amplifiers. Not in the photograph are a couple of transmitters,
receivers, and a couple of aerials that were bought for some future projects.
Some of the leads and fittings will be used to replace the ones taken out of
other units not being used at the time, and the rest for stock. It may look
like a lot, but when you take in to account the parts and modules used in a project,
such as the transmitter, receiver, amplifier, preamp, relays, coaxial leads and
aerial to be used, and the fact they all have to be joined together, it is a
wonder any RF gets out at all, and you would be left wondering

where did all
the leads that were bought go to.

Ouch

On the subject of
fittings and RF, in photo 2 above, you can see some fittings, some of the connectors
go as high as 24ghz, they are not exactly falling out of my hand and this lot
had not a lot of change out of €120. As with any radio rally those of you who
have attended rallies over the years would get to know the various sellers
selling equipment and also other traders and buyers who have dealt with them.
The fact that some of them have been in the business of designing and
manufacturing for years, and take pride in showing their equipment is 100%, they
would have the spec sheets of their products for you to inspect, some even go
to the bother of bringing some test equipment to show the buyer the equipment
running before you buy, even more important some of the traders would let you
know the ones that whose claims of their equipment would not live up to what is
stated on the label.

Bargain?

Prices can vary
quite a bit as some items can have less of a demand in one country than another,
and as a result you could buy well from one trader and in the next row of
stalls see the same quality of gear from someone else a lot dearer/cheaper than
the last trader, so when you have bought your parts for a steal, stop looking
for them at other stalls to see how well you done as you will feel like you
were robbed if you see them cheaper. The cheaper parts may just be that, cheaper,
or be a cheap brand that may not be up to the spec you need and all that lovely
RF will go any where but to the aerial.

In photos 3 and 4 above, you can see a couple of the amplifiers bought at the rally, one is for 5.7GHz
and the other is for 10GHZ .

Below in photo 5 shows some more fittings.

The worst part of this rally is not having my own car
with me, and seeing plenty that would fit nicely in the boot, not only the
various new pieces of equipment, but the “scrap parts”. One piece of equipment
bought was a repeater that could be modified for 10 GHz, these pieces of
equipment weighed a few kilos more than my total allowance on the aeroplane, I
would have loved to have brought a couple of the units home with me, not only
was the enclosure a nice size but was meant as a mast mounted unit and was
waterproofed and it only had the wave guide connector and a small multi plug for
the dc connections. Inside the unit, other than the TX/RX equipment, there
where some lovely fittings and brackets to be had, but as this item was
purchased on our last day at the rally we knew that the limits of our allowance
was getting close and something had to be left behind, as the extra charge
would have cost 5 times the amount paid for them, so knowing some of the
traders I got a loan of some tools and the parts wanted removed, and in these
recycling times, the metal container and other parts where given back to the
trader to sell to someone else, he was so happy to take them back he said that
we could have some of his other stock, as the container was a seller on its own
and it saved him the grief to disassemble it. As you know quality cost but I wished
it didn't cost that much, cheaper fittings and connectors could have being
bought but they would have being no good at the frequencies I wanted them for,
and as mentioned earlier the need to get as much of the RF out of the equipment
as possible and into the aerial, as one of the high power transmitters(or
should that be QRPP) bought can push out nearly 100mw and so some high end
connections (and a amplifier) will be used on this project that would be a
permanent outdoor unit, now where can I get a professional waterproof enclosure
to house everything and keep it dry and safe, (ah feck).

In this issue of the HX files I would like to take a
brake from the construction of a couple of items I have currently on the work
bench. A couple of parts are needed to complete both of them and I am hoping to
get those parts needed at the rally in Germany in June. Not wanting to remove
any parts from other projects (like I have done before) as these parts would mean
a total dismantling of the projects and this time that was not on.

And now, time for something
completely different.

So in this issue
of Echo Ireland I would like to write about some of my eclectic mix of
“collectables”. Some of these items were bought because of their “rarity” and
some because they are just plain weird; I will leave it up to you to decide
which is which.

The first items are a couple of ceramic insulators from
(I am told) an aeroplane, these would be placed either end of the plane and the
aircraft wire aerial would pass through it. In photo 1 bellow,you can see that each
has a couple of aluminium rings that attach it to the craft from both sides of
the aircraft's skin.

Number 17 set

In photo 2 above, you can
see one of the radios in the collection, it is a Second World War radio called
a “wireless set number 17”, there were two versions manufactured, the one I
have is the MK2, the MK2’s operating frequency is from 44 MHz to 61 MHz. Some
info for you power hungry hams out there, it could produce around 300 watts, nah
only joking, actually its power output is more like +/- 250 MW, and with either
one of its complement of aerials a distance of some 10 plus miles could be
“guaranteed” and that was more than enough as you did not want the wrong people
ear wigging. Its main use was to communicate from the ground support units of
Barrage balloons and Anti-Aircraft locations to HQ, and it replaced signalling
lamps( that would be used in the daylight as well as the night, and you did not
want the enemy pilots seeing the beam of the lamp at night). As there was a war
on, and metal was used for other things, the radio’s cabinet was not made from
metal but from wood, the manufacture used as much wood as they could in its
construction, I wonder if they tried to make the valves from wood and found
that they wooden work. Some details for those of you with no grey hair, it was
a ready to go rig and was powered by two 60v dry batteries in series and a 2v 16 ah accumulator. The No 17 used two valves, one each of an AR6 and AR18 type valve.
It was mentioned in a radio conversion book that told you how to modify some of
the ex-military radios that were available to the radio amateurs, that you
should leave the “No 17” set alone, as it would cause interference to other
radios close by even when it was in the receive position. The weight of the
radio is around 10kg, and its measurements (in inches are), 14½ W,16 H, and 10
D, it was made on a budget and when the
bombs were dropping you did not want to be carrying a big radio as you would
used your hands to keep your hat and trousers on whilst running for shelter. As
mentioned earlier, before the “No 17 set” there was the signalling lamp like
the one in photo 3 below.

The case contains the lamp, which had a removable red
filter for daytime use, also in the case was a stand made from some small
lengths of tubing that would screw together and then be stuck into the ground.
Also in the other compartment of the case would be the battery, and a spares
kit including a spare bulb. No space was
wasted, as the Morse key is mounted on the inside of one lid and the
instructions for its care and use on the other, also the lamp itself has a
couple of features, one is at the bottom, it is a small screw that when
loosened the lamb could then be easily tilted and lined up to the senders target,
and on the lamps top is a sighting tube. Not a telescopic sight but simply a
tube with a round hole at the sender/receivers end and a plus (+) shaped hole
at the target end , you might be able to make it out in the photo. In photo 4 below,

you can see some microphones, the bottom left one is a WW2 era throat microphone,
it was used in noisy environments like airplanes, top left is also a microphone
and not a ray gun from Flash Gordon, top right is a head set from a Marconi
marine base radio I think it is was called a triple diversity transceiver, and
the microphone on the bottom right is from another Army radio.

And finally

That is it for this issue of Echo Ireland; in a forth
coming newsletter I must mention some of the other military radios and Morse
code keys and other bits and pieces in the collection. Perhaps you could send
in an article yourself about some of your own collections of the weird and
wonderful.